Sometimes you start building, and the project evolves. Layers upon layers of functionality accrue, accrete, and otherwise just pile up. Or at least we’re guessing that’s what happened with [Varun ...

The objective of the project is to decode dual tone codes into digits which are later interpreted by microcontroller. This device is very useful for decoding Dual Tone Multi Frequency (DTMF) generated ...

Though many of us will never have experimented with it, most readers should be familiar with DTMF as the tones used by the telephone system for dialling. If your youth was not misspent mashing 4-4-2-6 ...

In the early 1960s, AT&T introduced a method of providing in-band signaling so telephone customers could place telephone calls. The system was called dual-tone multi-frequency, or DTMF. AT&T, through ...

Using dual-tone multi-frequency (DTMF) technology provided “touch-tone” service that would become the worldwide standard for telecommunication signaling. The system uses audible tones for each of the ...